Method of avoiding biometrically identifying a subject within an image
A method of image processing within an image acquisition device. In one embodiment an image including one or more face regions is acquired and one or more iris regions are identified within the one or more face regions. The one or more iris regions are analyzed to identify any iris region containing an iris pattern that poses a risk of biometrically identifying a subject within the image. Responsive to identifying any such iris region, a respective substitute iris region, containing an iris pattern distinct from the identified iris pattern to avoid identifying the subject within the image, is determined and the identified iris region is replaced with the substitute iris region in the original image.
1. A method of image processing within an image acquisition device, the method comprising:
storing one or more standard iris region images in storage;
acquiring an original image of one or more subjects, the one or more subjects including one or more image face regions, the one or more image face regions comprising one or more image iris regions;
analyzing the one or more image iris regions to identify an input iris region image, the input iris region image comprising an input iris pattern, the input iris pattern capable of being image processed and biometrically identifying one of the one or more subjects within said original image;
responsive to identifying the input iris region image, determining, from among the one or more stored standard iris region images, a substitute iris region image, the determined substitute iris region image comprising a substitute iris pattern distinguishable from the input iris pattern, the substitute iris pattern inhibiting identification of said one of the one or more subjects within said original image, wherein said determining the substitute iris region image comprises:
retrieving, from among the one or more standard iris region images stored in the storage, a first standard iris region image;
performing a blurring operation on the first standard iris region image to generate a blurred first standard iris region image;
performing first subsequent blurring operations on the blurred first standard iris region image to generate a plurality of blurred standard iris region images, each subsequent blurring operation of the first subsequent blurring operations increasing a blur of the first standard iris region image;
subtracting each blurred standard iris region image of the plurality of blurred standard iris region images from another blurred standard iris region image of the plurality of blurred standard iris region images to generate a plurality of detail standard iris region images;
performing a blurring operation on the identified input iris region image to generate a blurred identified input iris region image;
performing second subsequent blurring operations on the blurred identified input iris region image to generate a plurality of blurred input iris region images, each subsequent blurring operation of the second subsequent blurring operations increasing a blur of the identified input iris region image;
subtracting each blurred input iris region image of the plurality of blurred input iris region images from another blurred input iris region image of the plurality of blurred input iris region images to generate a plurality of detail input iris region images;
subtracting each detail input iris region image of the plurality of detail input iris region images from the identified input iris region image to generate a difference input iris region image; and
adding each detail standard iris region image of the plurality of detail standard iris region images to the difference input iris region image to generate the substitute iris region image.
2. The method of claim 1 , wherein the adding further comprises identifying an area of eye glint in the identified input iris region image and incorporating said eye glint in the substitute iris region image.
3. The method of claim 1 , further comprising transmitting or storing the substitute iris region image.
4. The method of claim 1 , wherein the step of acquiring an original image of the one or more subjects comprises acquiring a frame within a sequence of image frames and identifying and tracking the one or more face regions within the sequence.
5. The method of claim 1 , wherein the step of acquiring an original image of the one or more subjects comprises acquiring a still image.
6. The method of claim 1 , wherein the step of analyzing the one or more image iris regions comprises identifying an eye region within one of said one or more image face regions and assessing one or more of: eye size, focus, local contrast, and local sharpness to determine iris pattern quality.
7. The method of claim 6 , further comprising extracting iris regions from multiple eye regions, each extracted iris region comprising an iris pattern.
8. The method of claim 7 , wherein the step of analyzing further comprises assessing any combination of: whether an extracted iris region of the extracted iris regions is of a predetermined size or area; whether an extracted iris region of the extracted iris regions is of a predetermined shape; and whether an extracted iris region of the extracted iris regions exhibits a predetermined level of contrast.
9. The method of claim 1 , further comprising storing the substitute iris region image in the storage and wherein, responsive to identifying an iris region associated with a subject within said original image, said stored substitute iris region image is retrieved from the storage.
10. The method of claim 1 , wherein the step of analyzing further comprises determining an iris code for the input iris pattern or an error code for adjusting the input iris pattern.
11. The method of claim 10 , wherein said adjusting comprises adjusting a contrast of the input iris pattern.